Archive for the ‘testing’ Category

Dilshan Jayakody writes: This is simple Colpitts oscillator to test commonly available passive crystals which range between 2MHz to 27MHz. This unit must connect to an oscilloscope and/or frequency counter to get the frequency of the crystal. This circuit is design to work around 9V to 12V DC power source....

Kerry D. Wong writes: In the video below, I tested this DC-DC converter board under various operating conditions and measured its efficiencies. To conclude, these switching regulator boards are well suited for low to medium current draw digital circuitry but for higher current applications a heat sink is needed and...

Jan Cumps tested out SPI Protocol using a Bus Pirate: It wasn't my initial intention to use the Bus Pirate. But my first naive attempts to talk from Hercules to EEPROM failed. I could create the SPI instructions with the LaunchPad, but I didn't get a reply back from the 25LC256....

Jim writes: Since I use a variety of cells, I wanted to be able to charge at Chip2014under 1A. Most such charge controllers have a single resistor that programs the bulk charge current, so I looked for the datasheet to find what values I’d need for the charge currents I...

Kerry Wong writes: Hysteresis can be added to a comparator circuit to improve its stability, especially when the input signal is noisy. In this post, we will examine the hysteresis characteristics of some common comparator and Op Amps using an oscilloscope. Perhaps the most intuitive way to visualize the hysteresis...

KF5OBS writes: After posting the teardown video of the Tektronix RSA306 USB 3.0 Spectrum Analyzer on my YouTube channel, someone asked me to verify that the IF sampled by the Linear Technology 14-Bit / 125 Msps ADC is really at 140 MHz. Using the Tektronix MDO4104B-6 and a passive RF...

Rajendra over at Electronics Lab wrote an article on his temperature logger based on a Microchip's 8-pin microcontroller, PIC12F683: A data logger is a device that records measurements over time. The measurements could be any physical variable like temperature, pressure, voltage, humidity, etc. This project describes how to build a mini...

Kerry Wong writes: Transistors operating in their avalanche regions are often used to generate fast rise pulses (see avalanche pulse generator using 2N3904). Many transistors can also avalanche when the connections to collector and emitter are reversed. When operating in reverse avalanche region, these transistors are sometimes referred to as...

Kerry Wong writes: I was doing a project that needed a driver for hard disk spindle motors. While I could use a microcontroller to generate the required driving waveform sequence, keeping the waveform in sync with the motor rotation is actually quite tricky especially at higher rotation speeds. To ensure...

Bajdi did some tests for switch mode voltage regulators: There are different types of DC-DC regulators. The most common are linear and switch mode regulators. Everyone that has tinkered with electronics has probably used a 78xx series linear regulator. They are easy to use since they don’t need any special components....

mux writes: I've been doing some tests with the STM32F407 to see how fast it can go, STMicro has released an almost identical one that runs at 180MHz, is it a marketing thing ? will they release a 200MHz version in a few months? who cares, anyway, I was able...

63 resistor reels just arrived for a test 0603 OOMP part book. Books and sheets should be here tomorrow. We'll stuff some samples and get an idea of the time involved this weekend if everything goes smoothly.

Kevin Rye designed a simple LED tester:I decide to put together a small LED Tester board. It’ll be powered by a small coin cell battery. I can pick up an LED with a pair of tweezers and just simply tap it to the solder pads. If it lights up, I...

Baoshi writes: I bought some FT230X (FT230XS) USB-USART bridge chip recently for a new design. FT230X is not only cheaper than the traditional FT232RL, but also offers a new fancy “USB charger detection” function. This interests me because I’m quickly running out of desk space and power socket. I wish...

Viktor wrote a post on his blog detailing his DIY test leads: The result is that now I have proper test leads with resistance of less than 0.1 ohm per meter. This is a measurement of one of my new test leads Also, with this method now I can have as many test...

Kenneth Finnegan writes: As part of a few projects I'm working on, I want circuits to be able to decode DTMF tones played over an amateur radio link for remote control. This can be done with a moderately powerful processor in DSP, but I opted to buy a handful of...

Edouard gives us a preview of the new version of the in-line voltage/current tester board by FriedCircuits. He reports that the board is also compatible with the OLED Backpack (requires separate USB power source.) Via the contact form.

An ATmega32 based Proteus simulation of 16 line connectivity tester by Dilshan Jayakody: The main functionality of this system is to detect open and short circuits in cables and connectors. This system can test maximum of 16 lines in each test cycle and it indicate the defective line(s) through LCD. This...

Debraj built an electrical dummy load to test his power supply and wrote a post on his site detailing it’s assembly: Recently, I purchased a power supply that claimed a max current of 2A and 0~15V. So I wanted to test it. I had a 36 watts bulb (used in motor...

Alex over at InsideGadgets has posted an article describing how he built an ATtiny25 voltage controller oscillator (VCO): I recently bought a Rigol DS1052E and have been playing around with the different functionality it has. Eventually I came to the point that I’d like to see what frequency does to various...